First off i'd like to say that i haven't built a lot of mountain bike trails but i've been riding mountain bikes and motorcycles since the 70's. With that said and thinking about what i've read here and read receintly in dirt rag (new school trail design: have we gone too far) I think that the trails should have a new category of speed which would tell everyone what type of trail to expect, example 20mph trail - down hill, 2 mph trail- very tech you know what i mean? The pic by cmt4130 i wouldn't call a trail but a track. Here in the northeast pa i ride a lot of what can best be described as deer trail singletrack which is very rocky and has little flow. I think different parts of the country with all the different types of soils allow for many different types of trails but when we talk about them it means different things to different people. Berms for example don't really need to be that high to ride fast if there is good grip and you can hold your line, but a new rider skidding along can destroy a small berm with out even realizing he did so. So i think we all need to step back and think about terminology and the people who will be riding the trails. according to the article i mentioned less than 1% of the people out there riding mountain bikes can ride the tech lines.

I think you are right about the benefits of more specific signage TC. Some time back I posted examples of signs that broke the trail down into ascending/descending, distance, grade, speed, TTF and jumps. Each of these was rated green to double black. So you could have a trail that is green in grade, but with blue speed and blue TTFs, or you could have a climbing trail that is green in speed, but double black in grade and TTF.

The signs were shot down in flames on this forum - apparently there are enough legitimate signs out there without trying to provide more information for riders. Can't say I agree.

i was stoked to lead a work day yesterday to build a few new berms, hole patching, and drainage. this section of trail has a gradual descent for a while, so it's a great one for speed control and skid prevention, not to mention fun leaning into turns.

i like berm exits where you sort of blend a roller into the end of the berm and drop into a descent...

That's what my club (Berkley, myself, and a couple others) started building with 4 years ago. Not because anyone really said we should, but because we watched all the crazy DH and FR videos with their crazy flow lines and we wanted to incorporate a lot of that feel into our multi-use XC trails.

Our first effort was deemed Blood Sweat & Tears and took us 3 years to build just shy of 3 miles. We learned a lot along the way, often having to redo sections after what we did originally felt lousy or showed signs of erosion. Eventually we figured it out and the trail is by far the most heavily used trail in town now by hikers, runners, and bikers. The track & field and XC running teams in town (2 colleges and a high school) all love BST and run it for training. Upon being asked about it, their most common answer is "all the banked turns." I guess berms aren't just for bikes.

Since finishing BST we've built a couple other "flow country" trails that have been quite popular. The most recent efforts have resulted in a trail that has a descent in each direction that is essentially a jump line for XC bikes, and is still good to run. The next stage that we're laying out now and will start digging on soon links in with our super smooth flowy trails and is going to be super gnarly technical XC trail.

So I guess we're moving in the opposite direction for our next build after we put on a fair bit of the buffed out stuff over the past few years.

Do you think there is a correlation between berms incorporating the feature of a roller/descent at the exit and climbing berms? Reason I ask is a lot of descending berms cross the falline significantly and it can be an issue building inslope to outslope drainage past a roller. I understand you like BMX tracks and they don't climb. Also, is there a limit to the grade of land you can build this sort of berm?

. . . The track & field and XC running teams in town (2 colleges and a high school) all love BST and run it for training. Upon being asked about it, their most common answer is "all the banked turns." I guess berms aren't just for bikes..

Do you think there is a correlation between berms incorporating the feature of a roller/descent at the exit and climbing berms? Reason I ask is a lot of descending berms cross the falline significantly and it can be an issue building inslope to outslope drainage past a roller. I understand you like BMX tracks and they don't climb. Also, is there a limit to the grade of land you can build this sort of berm?

Second, have you guys built some monument in that tree?

I'm not sure I quite understand what you're envisioning when you're talking about climbing berms. You mean like a two-directional trail, where some riders will be riding up the berms that were designed for descent ? To me, if the trail is one-directional climb . . . you either don't need berms at all, or they would be much smaller/tighter radius.

I do look at the fall line and where the water is going. In this case none of the berms "caught" the fall line. Rather the trail was doing switchbacks across the fall line with berms basically at the switches.

This is an upgradient view of the big berm we just did. I would imagine that if you were riding upgradient, you wouldn't even really use the berm.

As far as "roller out," really I could have better described it as what bmx trails guys call a "waterfall" (see: Waterfall.jpg ) That's when you pump just the down side into a dip, kind of like the second half of a roller, without the "up." When you exit a berm, it's fun to be able to drop down to downward slant (landing) to pump...

Here's a short video of building and riding trails in Kincaid park which is a Anchorage's largest municipal park. Lots of banked corners, flow, and even a few roller doubles and table tops thrown in for good measure. Kincaid STA Trailer on Vimeo The trails where build by Single Track Advocates, a local trail advocacy group. Singletrack Advocates

Interesting thread and important. The advent of trail users in Motion (cyclists, runners etc..) has changed critical design considerations for trails. Flow to me means creating an route that anticipates user speeds and uses super elevation to keep the angle of the riders wheel perpendicular to the trail tread as it transitions through the terrain.

Managing the pitch and alignment to minimize the need to pedal or brake is similar to roller coasters and is helpful for developing intuitive design. Speed also impacts required sight lines. Braking bumps are the visible gang green of poor design.

The roller coaster comparison is perfect because they manage momentum in beneficial ways and design to create passively managed movement (minimal braking or thrust required).

I have found that designing and building snow luge runs is helpful to understand managing movement. The biggest mistake I often see is a chiseled berm vs a cupped berm. A flat angled berm (chiseled) does not graduate the level of centrifugal resistance or have a sweet spot. I have seen 8" tall cupped berms that will capture and 'rail' the rider through the turn with less lateral stress on the tread than a 3ft tall flat angled berm. Small cupped berms require less dirt and are lower profile.

We use a 1" sch40 PVC pipe 100+ ft long to check alignment transitions through terrain like an architect might use a ruler. Amplitude ratios to frequency are directly related to the anticipated speed of the rider. (less intense arcs the faster you go)

Interesting thread and important. The advent of trail users in Motion (cyclists, runners etc..) has changed critical design considerations for trails. Flow to me means creating an route that anticipates user speeds and uses super elevation to keep the angle of the riders wheel perpendicular to the trail tread as it transitions through the terrain.

Managing the pitch and alignment to minimize the need to pedal or brake is similar to roller coasters and is helpful for developing intuitive design. Speed also impacts required sight lines. Braking bumps are the visible gang green of poor design.

The roller coaster comparison is perfect because they manage momentum in beneficial ways and design to create passively managed movement (minimal braking or thrust required).

I have found that designing and building snow luge runs is helpful to understand managing movement. The biggest mistake I often see is a chiseled berm vs a cupped berm. A flat angled berm (chiseled) does not graduate the level of centrifugal resistance or have a sweet spot. I have seen 8" tall cupped berms that will capture and 'rail' the rider through the turn with less lateral stress on the tread than a 3ft tall flat angled berm. Small cupped berms require less dirt and are lower profile.

We use a 1" sch40 PVC pipe 100+ ft long to check alignment transitions through terrain like an architect might use a ruler. Amplitude ratios to frequency are directly related to the anticipated speed of the rider. (less intense arcs the faster you go)

Very well put. The roller coaster analogy does make sense.

Re cupped berms: There seems to be an angle (sidewall steepness) above which riders will not use the entire height of the berm, as well as making it hard to get adhesion from building materials. Over time a berm with a wall too steep develops an overhang as riders slot into a line eroding from use, but only part-way up the wall of the berm. It's probably the topic for another thread, but does anyone have a suggestion regarding maximum wall gradient on berms?

Re cupped berms: There seems to be an angle (sidewall steepness) above which riders will not use the entire height of the berm, as well as making it hard to get adhesion from building materials. Over time a berm with a wall too steep develops an overhang as riders slot into a line eroding from use, but only part-way up the wall of the berm. It's probably the topic for another thread, but does anyone have a suggestion regarding maximum wall gradient on berms?

Do not think there is a rule of thumb on this, then again I may be completely wrong. I think it would depend more upon your soil type and how well it is able to compact. If it is dense with good adhesion then you could go both steeper and higher especially if you armor it with a few rocks. If the soil is effectively beach sand the it might not hold up all that well over the long haul.

I'm working on my 4 kilometers loop second year now. Alone. In last year i made main trail without any pumps, obstacles etc. In this year i start working on these things. I hope the nature will not take away all back from me

Good on you! Here's a resource I found via mtbr forum which you might find useful.

Can anyone point me to some pics or video of hand-made, natural looking flow trail? ie: doesn't look like a bmx race track or made with bulldozers and mining equipment. Or is it not considered flow trail without jumps and wall-berms?

Can anyone point me to some pics or video of hand-made, natural looking flow trail? ie: doesn't look like a bmx race track or made with bulldozers and mining equipment. Or is it not considered flow trail without jumps and wall-berms?

There's a trail in the Revelstoke area (Mt MacPherson?) that has been built as a flow trail. I have no pics as I was having WAY too much fun to stop, but I'm sure they're out there.

Can anyone point me to some pics or video of hand-made, natural looking flow trail? ie: doesn't look like a bmx race track or made with bulldozers and mining equipment. Or is it not considered flow trail without jumps and wall-berms?

I'm just starting this one.

I have a device that can access the total knowledge of man. I use it to look at pictures of cats and argue with strangers.

Those two vids do look really fun to ride! Although I'm still reminded of a big pump track through the woods, but I suppose that is what flow trails are really meant to be. I think I'm looking for more of a XC flow experience with narrower tread. Should it still be called a "trail" if the tread is 6' wide??

Here are a few bad cell phone pics. My next plan is to accentuate the features, make those rolling grade dips into actual grade reversals by adding ~6" soil to the high points, but I have no intention of making tables or gaps out of them.

The sorba crowd seems to produce some great stuff, the last time I made a trip to NGa and WNC area, some of the new machine built stuff just blew my mind! Funny to think that 12 year's ago Tsali was one if the top 10 trails in the country. Now it barely makes the top 10 in the state of NC.

Can anyone point me to some pics or video of hand-made, natural looking flow trail? ie: doesn't look like a bmx race track or made with bulldozers and mining equipment. Or is it not considered flow trail without jumps and wall-berms?

Flow trail may just be trail with IMBA standard drainage and some creativity. It doesn't have to have jumps or berms, but if they can be added to the design where terrain allows them, then great, but they also have to "flow". If you can flow along it slowly, then you are a happy little noob. If you up the speed ante, then jumps and different lines come into play. We let the terrain and content of the soil select those features, rather than construct large as can be done in a bike park.

Flow trail may just be trail with IMBA standard drainage and some creativity. It doesn't have to have jumps or berms, but if they can be added to the design where terrain allows them, then great, but they also have to "flow". . . . .

I agree. But, just for the sake of word usage, let's not just call every xc trail that is a flowy a "flow trail."

I think that's why the original poster tried to come up with a new term "flow country."

"Flow trail" was explicitly a way of bringing rollers, berms, and some jumps into mountain biking and getting people used to the idea that they were okay on something other than a bmx track, pump track, or DH trail.

For example, last summer I checked out Tamarancho in Marin County, NorCal. The Loop is all traditional xc (and pretty exhausting!). But only the "Endor" section is called the "Flow Trail" and it is all downgradient or flat, with rollers berms, etc.

The problem with definitions is that they either come with baggage or ownership (including $ value). That trail in St Moritz does look really awesome, but I'd call it an XC trail. The section of trail in my last post averages 9%, has similar grade reversals, but is not ever going to look like Switzerland, or drop 2000 vertical m. It's also an XC trail.

To me Flow Trail is bike park trail all at a high skill level and Flow Country trail is fun trail that goes somewhere and offers optional challenges (one being pace), but I could be wrong so please keep posting beautiful pics like that last one to continue the stoke.

The problem with definitions is that they either come with baggage or ownership (including $ value). That trail in St Moritz does look really awesome, but I'd call it an XC trail. The section of trail in my last post averages 9%, has similar grade reversals, but is not ever going to look like Switzerland, or drop 2000 vertical m. It's also an XC trail.

To me Flow Trail is bike park trail all at a high skill level and Flow Country trail is fun trail that goes somewhere and offers optional challenges (one being pace), but I could be wrong so please keep posting beautiful pics like that last one to continue the stoke.